In all communication networks, an essential task to be addressed is how to synchronize the operation of the network and of the different equipment and components that form part of the network. Prior art provides many different approaches to address this task.
In most synchronous network systems, the operation of the entire network is strictly synchronized to a common synchronization source. In one example thereof, each node has its own direct connection to this common synch-synchronization source, which is thereby connected to directly synchronize the operation at each node of the network. In another example, synchronization is forwarded from the common synchronization source through the network as such to reach all network nodes in a top-down manner, forming a so-called synchronization spanning-tree within the net-work. In the latter example, each output port of a node is typically strictly synchronized according to synchronization signals received at a currently designated input port of said node.
However, prior art schemes for distributing a frame frequency within a network while maintaining a high synchronization quality to reduce jitter are complicated and often require the use of expensive components and solutions while placing stringent requirements on the tow-down hierarchy, the network jitter, and/or negatively affecting data transport delays within the system.
The object of the invention is therefore to provide a simple and effective solution that provides a relaxed more flexible basis when defining synchronization trees within a network and at the same time allows for optimization of the way in which synchronization is propagated at a node of the network.